Flashers



Feb. 4, 1958 Filed June 6, 1956 FIG. 1

G. COLOMBO ET AL FLASHERS 2 Sheets-Sheet l IN V EN TOR.

Feb. 4, 1958 G. COLOMBO ET AL FLASHERS Filed June e, 1956 2 Sheets-Sheet 2 FIG. 4

FIG. 3

m w W.

ATTORNEY Unite States Patent D FLASHERS George Colombo, East Rockaway, and Boris Orlov, Brooklyn, N. Y., assignors to Signal-Stat Corporation, Brooklyn, N. Y., a corporation of New York Application June 6, 1956, Serial No. 589,801

9 Claims. (Cl. 200-88) This invention relates to a novel, compact, and simple thermostatically operated, relay type flasher particularly useful in signaling systems for automotive vehicles.

Thermostatically operated switches are frequently used as flashers for lamp circuits, such as the signal lamps of automotive vehicles. The operating mechanism is usually a thermomotive element, such as a bimetallic strip or an expansible high resistance wire. The thcrmomotive element is arranged to make and break the flasher contacts by alternately heating and cooling.

The heating of the thermomotive element is effected electrically, as by connecting this element in the operating circuit of the flasher. In the normally closed type of flasher, the thermomotive element is connected in series with the main contacts of the flasher so that it is heated while the flasher contacts are closed. When the thermomotive element is heated sufliciently to open the contacts, its thus breaks its own heating circuit and thereupon cools to re-close the flasher contacts.

In the normally open type of flasher, a high resistance heating circuit for the thermomotive element is connected in shunt with the normally open flasher contacts, the current flow in such shunt circuit being insuflicient to effectively energize the load controlled by the flasher, as the element is heated to a preset value, it closes the flasher contacts, thus forming a low resistance shunt around itself. The element thereupon cools to reopen the flasher contacts and repeat the cycle.

Signaling systems for automotive vehicles frequently include pilot or indicator lamps flashed in synchronism or in alternation with the signal lamps. Generally, the pilot or indicator lamp circuits are controlled by the armature of a relay having an operating coil whose energization is controlled by the flasher. However, such combined flasherrelay devices have hitherto been relatively bulky, complicated and expensive.

In such recently issued U. S. Patents Nos. 2,706,227, 2,706,228 and 2,712,044, there is shown and described a thermostatically operated switch or flasher incorporating a novel snap action vane of electrically conductive material. This vane is provided with an initial bend about a right line extending across the vane by thinning or deforming the vane along this line in two or more spaced sections of the line, these sections being spaced at their inner ends from the center of the vane and also preferably spaced from the outer ends of the bent line. When such a vane is to be utilized in a snap action switch, such as a flasher, the vane is forcibly bent about another line, at an angle to the line of initial bending by applying force to the ends of such lines of initial bending. When such force is released, the vane snaps back to its initial bent position, the action closely resembling that of a toggle.

H With a vane initially deformed in such a manner, the locked up stresses or forces have loci on elliptical lines or zones having radii centered on the center or midpoint of the vane located on the line of initial deformation midway between the inner ends of the spaced or discontinuous deformation. If the vane is held or fixed at a point on 2,822,444 Patented Feb. 4, 1958 one of the loci, the remainder of the vane, during snapping thereof, pivots about such mounting point. The greatest effective force is exerted at the center of the loci, but very substantial force is also exerted by portions of the vane located on the loci at the opposite side of the deformation line from the fixed mounting point.

Such a vane may be eflectively used in a thermostatic snap action switch by restraining the vane in the stressdeformed position by attaching a high resistance wire or strip at each of its ends to the vane at the ends of the line of initial bending. This high resistance wire or strip thus forcibly holds the vane in a distorted position bent about a line angularly related to the line of initial bending. When the high resistance wire has electric current passing therethrough, it heats and expands. During the expansion of the wire, a point is reached at which the tension exerted by the Wire is overbalanced by the kinetic energy of the vane stored therein by bending the latter from its initial bent condition. At this point, the vane snaps back to its initially bent condition.

Such a vane may be effectively used as a switch by mounting a contact thereon at a point on the opposite side of the deformation line from the fixed mounting point. As the vane snaps back and forth, this contact engages and disengages a contact fixed relative to the vane mounting point.

U. S. Patent No. 2,706,228, mentioned above, is more particularly directed to such a snap action vane type of switch or flasher in which the necessity for a ballast resistance in the flasher circuit is eliminated by attaching a separate heat expansible vane operating strip or wire at each end to the vane, and wrapping an electrically insulated high resistance heating element about the vane operator to heat the same when the flasher is energized.

The present invention uses a snap action vane of this latter type to provide a novel relay type, thermostatically operated flasher. More particularly, the invention flasher includes a dielectric base having three terminals thereon, preferably in the nature of prongs for insertion into a suitable electrical receptacle. The first of these terminals is arranged to be connected to the vehicle battery or generator, the second to the signal circuit control or selector switch, and the third to the pilot or indicator lamps.

A relatively flat, thin relay core of electrically conductive paramagnetic metal is mounted on the base and electrically connected to the second, or switch, terminal. The relay core has a first integral extension on which the snap action vane is mounted, and a second integral extension carrying, in insulated relation, a contact engageable with a contact carried by the movable part of the vane. This core mounted contact is connected to one terminal of the relay winding, and the other end of the relay winding is connected to the first base terminal, prong, or blade.

A high resistance, insulated heating wire is wrapped around the vane operating strip and connected at one end thereto and at the other end to the first base terminal or blade.

The relay core has a pair of arms forming an air gap, and a conductive paramagnetic armature is movably mounted on one of these arms with its free end overlapping and normally spaced from the other arm of the air gap. When the relay is fully energized, the free end of the armature is drawn toward such other arm to engage the first base terminal.

When the signaling circuit switch is closed, current flows in a series circuit including the high resistance heating wire, the vane operating strip, the vane, the relay core, and the signaling circuit. As the high resistance wire heats the vane operator, the latter expands and the vane snaps to engage the vane and core contacts. This shunts 3. the heating wire and closes a second circuit including, in series, the battery, the relay winding, the core and vane contacts, the vane, the relay core, and the signaling circuit.

When the first series circuit, including the high resistance winding, is closed, the current flow, due to the high resistance winding, is insufficient to operate the relay or efiectively illuminate the signal lamps. However, upon closing of the second series circuit, shunting the high resistance winding, the current flow is sufiicient to light the signal lamps and operate the relay. The relay armature is thereby closed against the third base terminal to light the pilot lamp. As the shunted heating wire cools, the vane operator contacts to snap the vane to the contacts open position, and the cycle repeats. Q

For an understanding of the invention principles, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing. In the drawing:

Figs. 1 and 2 are, respectively, opposite side elevation views of a flasher embodying the invention, the flasher cover being shown in section;

Figs. 3 and 4 are, respectively, opposite end elevation views of the flasher, with the cover in section; V

5 is a plan view of the flasher with the cover removed; and

Fig. 6 is a schematic wiring diagram of the flasher as incorporated in a directional signaling system for automotive vehicles.

Referring to Figs. 1 through 5, the snap action vane 13* incorporated in the flasher, and its thermomotive operating means, are substantially identical with the corresponding elements of U. S. Patent No. 2,712,044: Vane is preferably made of relatively thin electrically conductive spring metal, with consideration being given to its spring factor, stiffness, temperature coefficient, and the like, in accordance with the desired rate of operation of the snap action.

To provide an initial. set to vane 10 and to give'the same some depth so that it will resemble a beam in its action, the vane 10, which is shown as a substantially rectangular vane, is deformed or thinned along diagonal interconnecting corners 11 and 12. This vane deformation is preferably effected by linearly embossing the vane along the line 11-12 in two elongated spaced portions or bosses 15. i T

Due to the bosses, 15, 15, the sections 13 and 14 of the vane on either side of lin 1112 bend upwardly so that the vane assumes the form'of a shallow V having its apex on line 11-42. When vane bending forces are applied to the end of line 11 12, and the value of these forces equals or over-balances the inherent tendency of the vane to stay in its present condition, the vane snaps into a new bent or deformed position, forming another shallow'V along the other diagonal 1617. When the forces at points 11 and 12 are decreased to a point where they are overbalanced by the kinetic energy stored in vane it} due to such distorting force, the vane snaps back to a position bent along the line 11-12. j

Photographs, taken with polarized light, of a transparent vane formed in this manner show lines of force in the unmarred center area of the vane which comprise elliptical bands having radii centered on the vane center, if the vane is secured or supported at a point onone of these elliptical stress loci, the stress points on the vane during application of bendingtorce at corners 11 and 1?; occur within the lengthof bosses 15. Thus the stresses are removed from the center area'and distributed between two points spaced from the center. This greatly prolongs the period before fatigue takes place in the stressed section of the vane,

Advantage may be taken of the foregoing by supportiug vane lit? by electrically and mechanically securing the vane, at a point on one of such elliptical lines of force,

to the electrically conductive paramagnetic metal core 20 of the flasher relay, and by electrically and mechanically securing a contact 13 to Vane 10 on the vane mounting surface out on the opposite side of line 11-12 from the vane mounting point.

In accordance with the invention, an indirectly heated, heat expansible element 44 of conductive metal is secured, in contracted relation, to the bent corners 11 and 12 of the vane. 10, by soldering or spot welding the ends of element 40 to vane 10, and is effected while the vane is stress-deformed aboutthe diagonal 1617. Thereby, when element 40 is heated and expanded a predetermined amount, the kinetic energy in vane 10 will overbalance the tension of element 40 and snaps the vane to its restored position in which it is bent about the diagonal 112.

Element 46 is heated by a high resistance insulated wire 45 wrapped around the element and having one end electrically connected thereto.

Relay core or frame Ztl is generally flat and relatively thin but rigid, and is supported on dielectric base 39 of the flasher. Three contact blades or terminals 31, 32 and 33 are secured to the undersurface of base 3%, as by rivets 31, 32', 33' extending through the base and connecting the bent inner ends of the blades to the base.

Core 20 has a bent arm 21 brazed, soldered or welded to rivet 32' and thus electrically connected to blade or terminal'32. An arm 22 bent outwardly and then upwardly from the upper end of core 2% has vane 1i electrically and mechanically secured thereto. Another arm 23 bent outwardly and then upwardly from the lower edge of core 2% carries aninsulating sleeve 24 on which is wrapped a flat conductor 2% carrying a contact 27 engageable with vane contact 18.

The central part or body 28 of core 20 carries the relay winding 25 of relatively heavy insulated wire. Winding 25 has one end connected to rivet 31' of blade 31 and its other end connected to contact 27. One end of high resistance winding 45 is also connected to rivet 31.

Arms 34, 36 projecting laterally from body 28 provide an air gap in the magnetic circuit of core 20. Upper arm 34 has a slightly bent vertical extension to' which is mechanically and electrically secured a thin spring leaf 37 of conductive metal. Spring 37 supports a conductive paramagnetic armature 35 extending across the air gap and overlapping lower arm 36. The bend of the extension of arm 34 biases the free end of armature 35 away from arm 35. The free end of armature is formed as a contact 38 engageable with rivet 33' of blade or terminal 33. Stop 39 limits outward movement of armature 35.

The operation of the device will be understood from Fig. 6 and the following description. The unit is inserted into "an appropriate receptacle so that blade or terminal '31 is electrically connected to one side of a grounded battery or other source of electrical energy55, blade 32 is connected to the armature 51 of a selector switch 54), and blade 33 is connected to a grounded pilot or signal lamp PL. Contact 52 of switch 55 is connected to parallel, grounded signal lamps SL and contact 53 of switch 55 is connected to parallel grounded signal lamps SL.

When switch arm 51 is closed to engage one of the contacts 52 or 53, a first series circuit is completed as follows, assuming that both signal lamps, such as SL, are fully operative: ground, battery 55, blade 31, rivet 31', high resistance wire 45, element 4t), vane 10, arm 22, core 20, arm 21, rivet 32', blade 32, switch arm 51, contact 52, lamps SL in parallel and ground. Due to the resistance of wire 45, thecurrent flow is insufficient to light lamps SL. Wire 45 heats up, heating element 4%, element .9 expands and vane 10 snaps to engage its contact 18 with relay core contact 27'.

Engagement of contacts 1827 completes a second series circuit, shunting wire 45, as follows (from rivet 31'); relay winding 25, contacts 2713, vane 11 core arm 22, and thence as previously described. The current flow is now sufiicient to light lamps SL and pick-up the relay (if both lamps SL are operative). Armature 35 is pulled toward arm 36 to engage contact 38 with rivet 33' and thus close the energizing circuit for pilot lamp PL which is thus illuminated in synchronism with signal lamps SL.

Element 40 now cools and contracts to snap vane back to its stress-deformed condition, disengaging contacts 1827 to extinguish lamps SL and drop the relay to break the circuit for lamp PL, and the cycle then repeats.

When the relay is energized, there is a magnetic attraction exerted on vane 10 by core 20 which resists disengagement of contacts 1827. When the stress etfect of element 40 is finally suflicient to overcome this magnetic attraction, there is very much pronounced snapping of the contacts out of disengagement, thus greatly reducing the effects of any arcing at these contacts.

Should one of the parallel signal lamps be defective, the current flow in winding will be insufficient to pick up the relay, so that pilot lamp PL will not be lit when switch 50 is closed. This will indicate to the observer a defective condition of the signal lamps.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

l. A flasher and relay unit comprising, in combination, a relay core of electrically conductive paramagnetic metal; a relay winding on said core; a contact mounted in insulated relation on said core and connected to one end of said winding; a snap action circuit closer mounted on said core in electrically conductive relation therewith; said contact being engageable by said circuit closer; thermostatic means, including a heat expansible electrical conductor mounted on said circuit closer, normally biasing said closer away from said contact; said thermostatic means, when heated due to current flow in said conductor, releasing said closer to engage said contact; a first terminal commonly connected to said conductor between its ends and to the other end of said winding; and a second terminal connected to said core; the ends of said conductor being electrically connected to said circuit closer to complete an initial series circuit including said first terminal, said conductor, said circuit closer, said core and said second terminal; said circuit closer, when engaged with said contact, completing a second series circuit, shunting said conductor, and including said first terminal, said winding, said contact, said circuit closer, said core and said second terminal.

2. A flasher and relay unit comprising, in combination, a relay core of electrically conductive paramagnetic metal having an air gap; a relay winding on said core; a contact mounted in insulated relation on said core and connected to one end of said winding; a snap action circuit closer mounted on said core in electrically conductive relation therewith; said contact being engageable by said circuit closer; thermostatic means, including a heat expansible electrical conductor mounted on said circuit closer, normally biasing said closer away from said contact; said thermostatic means, when heated due to current flow in said conductor, releasing said closer to engage said contact; a first terminal commonly connected to said conductor between its ends and to the other end of said winding; a second terminal connected to said core; the ends of said conductor being electrically connected to said circuit closer to complete an initial series circuit including said first terminal, said conductor, said circuit closer, said core and said second terminal; said circuit closer, when engaged with said contact, completing a sec- 0nd series circuit, shunting said conductor, and including said first terminal, said winding, said contact, said circuit closer, said core and said second terminal; an armature movably mounted on said core to extend across the air gap, said armature being movable to close the air gap When said winding has a predetermined current flow therethrough and being electrically connected to said core; and a third terminal engaged by said armature when the latter is moved to close the air gap.

3. A unit as claimed in claim 2 including a dielectric base mounting said core and said terminals.

4. A unit as claimed in claim 2 in which said core has a body on which said winding is disposed and a pair of arms extending from said body to form said air gap; said armature being mounted on one arm and extending across the other arm in normally spaced relation thereto.

5. A unit as claimed in claim 4 in which said armature is of electrically conductive paramagnetic material and is supported by a flat spring on said one arm.

6. A unit as claimed in claim 2 in which said thermostatic means comprises a heat expansible electrically conductive metal strip secured at each end to said closer and normally restraining said closer in stress-deformed condition, and a high resistance electrical conductor wound on said strip in heat transfer relation thereto and connected between said first terminal and said strip intermediate the ends of the latter.

7. A unit as claimed in claim 2 in which said circuit closer is a snap action metal vane mounted at a fixed point on said frame and with its free portion carrying contact means engageable with said contact.

8. A unit as claimed in claim 2 in which said circuit closer is a snap action metal vane mounted at a fixed point on said frame and with its free portion carrying contact means engageable with said contact; said thermostatic means comprises a heat expansible electrically conductive metal strip secured at each end to said closer and normally restraining said closer in stress-deformed condition, and a high resistance electrical conductor wound on said strip in heat transfer relation thereto and connected between said first terminal and said strip intermediate the ends of the latter.

9. A unit as claimed in claim 3 in which said terminals are contact blades projecting from said base.

References Cited in the file of this patent UNITED STATES PATENTS 2,103,276 Schmidinger Dec. 28, 1937 2,103,277 Schmidinger Dec. 28, 1937 2,354,635 Harmon July 25, 1944 2,639,345 Sitzer May 19, 1953 2,706,228 Welsh Apr. 12, 1955 2,715,187 Schmidinger Aug. 9, 1955 FOREIGN PATENTS 475,870 Germany May 4, 1929 

